Entry level dSLR cameras are less sophisticated and have no weather sealing, so they have a smaller form factor. The semi-pro cameras will be larger and bulkier. If you have large hands, you may find it hard to grip an entry level camera. If you have very small hands, you may find it hard to grip a semi-pro camera.
Most functions on an entry level camera have to be changed on the LCD screen, which means that you have to take your eye off the viewfinder. You have to hold the camera way from you and scroll through menus to adjust settings. This may cause you to miss some shots. With semi-pro cameras, you can change almost all the important settings without taking your eye off the viewfinder. Most of the important settings have a dedicated button (ISO, white balance, AF, etc). Dedicated buttons and the ability to change settings quickly is very important to event photographers and journalists.
Autofocus and frame rate
The autofocus systems are better and the frame rates are higher on semi-pro dSLR cameras compared to entry-level ones. You get what you pay for. If you shoot sports or wildlife, you are better off with a semi-pro camera.
Semi-pro dSLR cameras have some weather-sealing. Some even have professional grade weather sealing. The Canon 7D supposedly survived a trip to Antarctica. Entry level dSLR cameras don't have weather sealing. If you are using an entry level camera in rough conditions, I would recommend bringing a weather cover for the camera and lens.
Entry level cameras are lighter than semi-pro cameras because they are made of plastic. Semi-pro cameras have a metal frame which is more durable.